New CVEs in Ollama & DAEMON Tools; Webhooks Lack Signature Checks

Today's Highlights

This week's security highlights include a critical unauthenticated memory leak in the Ollama LLM framework and an ongoing supply chain attack targeting DAEMON Tools software. Additionally, a large-scale scan exposed that over a quarter of web applications fail to validate Stripe webhook signatures, leaving them vulnerable to payment bypasses and fraud.

Popular DAEMON Tools software infected – supply chain attack ongoing since April 8, 2026 (r/netsec)

Source: https://reddit.com/r/netsec/comments/1t4ajhu/popular_daemon_tools_software_infected_supply/

This report details a significant supply chain attack targeting the widely used DAEMON Tools software, a popular utility for mounting disc images and managing virtual drives. The attackers managed to compromise the software's distribution channel, injecting malicious code into legitimate updates. This allows them to distribute tampered versions of the software to unsuspecting users. The attack has been ongoing since April 8, 2026 (note: the original source date appears to be a typo, likely indicating a recent or ongoing campaign).

Supply chain attacks pose a critical risk as they exploit the trust users place in software vendors. By compromising a popular application like DAEMON Tools, which often requires elevated system privileges, attackers gain access to a broad user base. This foothold can potentially lead to the installation of backdoors, comprehensive data exfiltration, or further system compromises on affected machines, bypassing traditional perimeter defenses. This incident underscores the necessity for robust software integrity verification, multi-factor authentication for developers, and constant vigilance against tampering throughout the software development and distribution lifecycle. Organizations and individual users are urged to verify the authenticity and integrity of all software downloads and updates, especially for applications like DAEMON Tools that interact deeply with the operating system. Implementing software whitelisting and regularly auditing software provenance can help mitigate such risks.

Comment: Another day, another supply chain attack on a widely used tool. It's a stark reminder that even trusted software can be weaponized. Companies need to look beyond their own perimeter and secure their entire software delivery pipeline.

Bleeding Llama: Critical Unauthenticated Memory Leak in Ollama (CVE-2026–7482) (r/netsec)

Source: https://reddit.com/r/netsec/comments/1t4q8zd/bleeding_llama_critical_unauthenticated_memory/

A critical vulnerability, dubbed "Bleeding Llama" (CVE-2026–7482), has been discovered in Ollama, a popular open-source framework for running large language models (LLMs) locally on a personal machine or server. This unauthenticated memory leak allows remote attackers to potentially extract sensitive information from the Ollama server's memory without requiring any form of authentication or prior access. The vulnerability resides in how Ollama handles specific requests, leading to inadvertent disclosure of memory contents.

The ability to perform an unauthenticated memory leak is extremely dangerous, as it can expose a wide array of confidential data. This could include API keys, user-specific data, sensitive prompts, model weights, or other confidential operational details stored in memory during an LLM's operation. Such information could be used for further exploitation, intellectual property theft, or privacy breaches. This vulnerability highlights the emerging and unique security challenges in the rapidly evolving AI landscape. As more organizations and developers deploy LLMs in production environments, the attack surface significantly expands, and traditional security models may not adequately cover the unique risks associated with AI models and their local serving infrastructure. Defenders need to prioritize securing LLM endpoints, implementing strict access controls, and continuously monitoring for memory corruption and information disclosure vulnerabilities. Users of Ollama are advised to apply patches immediately as they become available and to review network exposure of their Ollama instances to mitigate this severe risk.

Comment: An unauthenticated memory leak in an LLM serving tool is a nightmare scenario. It shows how critical it is to apply traditional security rigor to AI infrastructure, especially when it handles sensitive data or models. Patch immediately.

We probed 6,000 web apps for Stripe webhook signature checks. 1,542 don't bother (r/netsec)

Source: https://reddit.com/r/netsec/comments/1t45sa6/we_probed_6000_web_apps_for_stripe_webhook/

A recent scanning project revealed a concerning trend: a significant number of web applications—specifically 1,542 out of 6,000 probed—are failing to validate Stripe webhook signatures. This widespread omission creates a critical vulnerability where attackers can forge checkout.session.completed events or other webhook notifications, essentially tricking an application into believing a legitimate event occurred when it did not. This can lead to severe consequences such as payment bypasses, unauthorized account actions, or other fraudulent activities, directly impacting revenue and user trust. Stripe webhooks are designed to inform applications about various events in a user's Stripe account (e.g., successful payments, subscription updates), and signature verification is the primary mechanism to ensure these notifications genuinely originate from Stripe and have not been tampered with in transit.

The lack of webhook signature validation is a common and often overlooked oversight in application security, frequently stemming from developer unfamiliarity with security best practices or pressures to rapidly implement features. Properly implementing signature checks involves comparing the signature sent in the Stripe-Signature header with a hash generated locally using a shared secret provided by Stripe. This cryptographic verification is a fundamental security control that prevents attackers from injecting false data or replay attacks into an application's backend. Developers are strongly encouraged to immediately review their webhook processing logic for all third-party services that utilize webhooks (not just Stripe) and ensure robust signature verification is in place. This proactive measure is crucial to protect against data integrity, authorization vulnerabilities, and potential financial losses.

Comment: This is a classic 'easy to miss, critical if you do' vulnerability. Always, always verify webhook signatures for all third-party services. If you're not doing this for Stripe, chances are you're not doing it for other services either. Huge attack surface that's often overlooked.